The two tech companies collaborated last week with other members, who remained nameless, of the security community in action against the hacking group, said both companies and an official from the White House on Tuesday.

Known as Lazarus or ZINC, they had been linked to ongoing threats online, including the past spring’s WannaCry attack that targeted banks, businesses and hospitals.

The news of the collaboration came on the same day the U.S. government made a formal accusation against North Korea for being behind WannaCry. The Homeland Security Advisor said that following careful investigation, the U.S. publicly was putting the blame on the government of North Korea for that attack.

The governments of Australia, Canada, Japan, New Zealand and the United Kingdom also made an announcement that they believed that attack was led by North Korea.

Though Microsoft and Facebook did not attribute the attack directly to North Korea, Brad Smith the president of Microsoft said in a blog post that the company was pleased the governments made those strong statements of attribution.

Smith wrote that if the rising number of attacks by nations on civilians is to be ended, governments must be ready to call the countries out that are behind the launching of the attacks.

The announcement by Facebook and Microsoft represents a big step in private sector and government actions to make today’s internet safer, wrote the security adviser.

Microsoft said it had cleaned the infected computers of its customers and took accounts down that Lazarus had been using to pursue more cyberattacks. The tech giant also increased its security on Windows to prevent the malware from being able to infect computers again.

Facebook deleted profiles that were being operated by Lazarus. Hackers used fake profiles on social media to pose as others and connect with their potential targets, said Facebook in its post.

It reached out as well to people who inadvertently connected to accounts it called suspicious, and gave them much needed advice on ways to improve their own security.

Facebook added that while it was going after the same group, it did not focus its actions directly on WannaCry. The companies approached the U.S. government to inform it recently of what they found.

The malware locks down computers that are infected and demands to be paid a ransom by the user. If that amount is not paid data will then be deleted.